イオン液体との複合構造を持つ(Bi, Sb)₂Te₃系熱電変換材料の作製とその熱電特性の評価

抄録

The composite of (Bi_0.3Sb_0.7)₂Te₃ and ion liquid, BMImTFSI, was synthesized by the immersion of the ion liquid to the pores of the porous sintered (Bi_0.3Sb_0.7)₂Te₃, and its microscopic structure and thermoelectric properties were investigated. The Seebeck coefficient of the composite is smaller than that of the porous sintered (Bi_0.3Sb_0.7)₂Te₃, while the electrical resistivity of the composite is a little larger. The thermal diffusivity of the composite is smaller than that of the porous sintered (Bi_0.3Sb_0.7)₂Te₃, which seems to indicate that the interface between the ion liquid and the crystal grain of (Bi_0.3Sb_0.7)₂Te₃ can be effective for the enhancement of the phonon scattering. As a result, the dimensionless figure of merit ZT of the composite shows the smaller value than the porous sintered (Bi_0.3Sb_0.7)₂Te₃.